“We have been prohibited from spying…
It has been reported that a man was brought before Abdullah bin Mas`ud (May Allah be pleased with him) because his beard was giving out smell of wine.
Ibn Mas`ud said:
“We have been prohibited from spying (on Muslims) and finding faults (with them). But we can take to task only and only if the sin is overt.
[Abu Dawud and the hadith is hasan sahih and meets the condition of bukhari and muslim].